There are a growing number of computer applications in which the physician directly interacts with a computer to provide patient care. Many of these are tested applications that could be economically implemented. However there is a lag in the diffustion of this technology. The primary objective of this research is to design, implement, and evaluate a program to increase physician use of a hospital information system (HIS). The program will use physicians who are identified as educationally influential in the communication network on each hospital service to disseminate information concerning the value of developing and using personal order sets (POS) for direct order entry into the HIS. In a previous NCHSR project, data on 650 members of Methodist Hospital's medical staff were collected by administering a questionnaire and by creating an abstract of the HIS purge tapes. These data will be used: (1) to describe the communication networks among physicians on 12 hospital services, (2) to identify educationally influential physicians in each of these networks, and (3) to generate baseline measures of attitudes toward the HIS and physicians use of the system. The project will involve four phases. First, educationally influential physicians identified on each hospital service will be recruited to participate in this project. Second, a training program will be designed to increase these physicians' awareness of the value of using personal order sets for direct order entry into the HIS. Third, two experimental programs will be implemented successively on 12 hospital services at three month intervals. Influential physicians will be exposed to training programs at the beginning of the project and again three months later. Data on HIS use by all physicians on the 12 services will be collected three months after each of the training programs to determine whether changes in physicians use of the HIS have occurred as a result of the programs. Fourth, a three factor experimental design with repeated measures on the intervention factor (i.e., the experimental programs) will be used to analyze the data. A major advantage of this design is the control that it provides over individual differences between physicians.